Semi-Active Rectifier Based Single-Stage Wireless Battery Charging System with Dynamic Tuning Capability for Electric Vehicles

In order to charge the Li-ion battery efficiently and safely, a novel single-stage wireless battery charging system (WBCS) based on the semi-active rectifier (SAR) and the switch-controlled capacitor (SCC) in receiver side are proposed in this paper. SAR is used for implementing constant current (CC)-constant power (CP)-constant voltage (CV) charging profile and SCC is used to compensate the reactance caused by SAR so that the WBCS can maintain the tuning condition. To realize the CC-CP-CV charging and dynamic tuning simultaneously, real-time impedance calculation (RIC) method is introduced. Since the control strategies are based on fixed switching frequency and receiver-side regulation, wireless feedback communication is not required, leading to improved system reliability. A 900W prototype is built to verify the validity of the proposed WBCS. The experiment results show good performance and efficiency improvement for the WBCS in the whole charge process.